This invention relates generally to the field of insulated surgical scissors and more particularly to both monopolar and bipolar scissors constructions that can be specifically adapted for use in laparoscopic, endoscopic and open surgery surgical procedures.
Insulated forceps, biopsy devices and clamping devices having the capability of providing a coagulating function are known in the art. These devices provide a significantly different function and have different design considerations than insulated scissors of the type forming the subject matter of this invention.
For example, forceps are principally designed to grip and hold tissue and/or organs during a surgical procedure; not to sever tissue between cooperation cutting edges of blades that move past each other to provide the severing operation, as in the operation of scissors within the scope of this invention. This prior art directed to the construction and design of insulated, cauterizing forceps are not relevant to the insulated scissors of this invention. Representative surgical forceps are disclosed in U.S. Pat. No. 5,217,460 (Knoepfler); U.S. Pat. No. 5,116,332 (Lottick), U.S. Pat. No. 5,026,370 (Lottick); U.S. Pat. No. 4,671,274 (Sorochenko); U.S. Pat. No. 4,890,610 (Kirwan, Sr., et al.); U.S. Pat. No. 5,147,357 (Rose, et al.); U.S. Pat. No. 4,375,218 (DiGeronimo); U.S. Pat. No. 4,128,099 (Bauer); U.S. Pat. No. 1,813,902 (Bovie).
Biopsy instruments also provide a significantly different function, and have different design considerations than the insulated scissors of the type forming the subject matter of this invention. In particular, biopsy devices are designed to separate and remove (often within a closed compartment of the device) portions of body tissue, growths, etc. from a patient""s body. In distinction to biopsy devices, the function of insulated scissors within the scope of this invention is to sever tissue or other body parts between relatively movable cutting blades, without necessarily having any separate capability to confine the severed tissue and/or body part and remove it from the patient""s body. Thus, prior art directed to the construction and design of insulated, cauterizing biopsy devices are not relevant to the insulated scissors of this invention. Representative surgical biopsy devices are disclosed in the following publications: U.S. Pat. No. 5,373,854 (Kolozsi); U.S. Pat. No. 5,295,990 (Levin); and European Patent Application 0 593 929 A1 (United States Surgical Corporation).
A wide variety of surgical xe2x80x9ccut and coagulationxe2x80x9d scissors also are known in the prior art, as exemplified by U.S. Pat. No. 5,573,534 (Stone); U.S. Pat. No. 5,356,408 (Rydell); U.S. Pat. No. 5,352,222 (Rydell); U.S. Pat. No. 5,342,381 (Tidemand); U.S. Pat. No. 5,234,453 (Smith, et al.); U.S. Pat. No. 5,171,256 (Smith, et al.); U.S. Pat. No. 5,147,356 (Bhatta); U.S. Pat. No. 4,499,899 (Lyons, III). As noted above, surgical scissors are utilized for purposes that are significantly different from the previously identified coagulating biopsy or forceps devices.
John M. Levin, the inventor of the subject matter described and claimed herein also is the inventor of the insulated cut/coagulate surgical scissors disclosed in U.S. Pat. No. 5,827,281 (Levin), whose entire disclosure is incorporated by reference herein. The scissors disclosed in the ""281 Levin patent have a monopolar or a bipolar construction, which can be used during laparoscopic, endoscopic and open surgery for mechanically/electrically cutting and coagulating tissue. The jaws of these surgical scissors are covered in their entirety by insulation except for selected portions along the cutting edges and the tips to minimize undesirable burning/cutting of surrounding tissue. The present invention relates to modified forms of the insulated scissors described in the Levin ""281 patent.
The apparatus disclosed by Stone is a bipolar electro surgical instrument comprising jaws fabricated from an insulating material having conductive pathways. These conductive pathways permit sparking between the pathways when the jaw members are open. As the jaw members are brought together, the insulating jaw member material blocks the electrical path between the conductive pathways to terminate electrical treatment of tissue trapped between the jaw members.
The apparatus disclosed by the Rydell patents are surgical scissors with a bipolar coagulation feature. The scissors disclosed therein comprise a pair of opposed blade members pivotally joined to one another through an insulated bushing member. Each of the blade members comprises a blade support and a blade, each fabricated from a metal but yet separated by a dielectric bonding agent. Cutting is performed at the blade level and cauterization occurs through the passage of electricity from one blade support and through the tissue to the other blade support. In other words, the passage of electricity is not through either of the blades that cut the tissue. Instead, electricity flows from one blade support (above and below the cut made by the blades), through the tissue trapped between the blade members, and into the other blade support.
The apparatus disclosed by Tidemand is a combination bipolar scissors and forceps instrument. The scissors disclosed therein comprises a pair of interfacing blade surfaces. Each of the interfacing blade surfaces comprises an insulative ceramic layer of approximately 0.020 inches. During scissoring action, a gap of approximately 0.040 inches is created between the interfacing scissors surfaces. Tidemand states that this gap is small enough to allow an RF current applied to the interfacing blade members to xe2x80x9cbridgexe2x80x9d the gap and effect a cauterization on any tissue trapped between the blades.
The apparatus disclosed by Smith, et al. (""453) is a disposable laparoscopic scissors utilizing cobalt-based alloy scissor elements that can be double acting (two movable jaws) or single acting (a single movable jaw in combination with a fixed jaw) and includes a plastic shrink wrap applied to the aluminum tube.
The apparatus disclosed by Smith, et al. (""256) is also a disposable laparoscopic scissors that can be double acting or single acting and includes plastic shrink wrap applied to the aluminum tube and portions of the actuation means at the working end of the instrument to electrically insulate the instrument.
The apparatus disclosed by Bhatta is a scissors-like surgical instrument with a cutting and cauterizing heat source such as a hot wire element or a laser transmission fiber carried in at least one of the jaws members.
The apparatus disclosed by Lyons, III is a rotary cutting scissors for microsurgery that includes an internal fiber light source for illuminating the surgical area.
Even in view of the above-described prior art disclosures, a need still exists for improved surgical scissors construction that allows the surgeon to cut tissue and to immediately coagulate the opening created by the cut while at the same time minimizing or eliminating any burning of surrounding tissue. In addition, it is important to be able to restrict the electric current flow through the patient""s tissue when using such an apparatus.
An apparatus for cutting and cauterizing tissue during surgery while minimizing electrical and thermal contact of the apparatus with surrounding tissue. The apparatus comprises: a pair of opposing electrically conductive cutting blades pivotally connected to allow for shearing action of any tissue confined between opposed cutting edges of the cutting blades wherein the blades have blunted tips and wherein the pair of opposing cutting blades are entirely covered with an electrically and thermally insulative material except at the blunted tips; and a power source coupled to at least one of said pair of opposing cutting blades for electrically and thermally energizing at least one of said pair of blades.
An apparatus for cutting and cauterizing tissue during surgery while minimizing electrical and thermal contact of the apparatus with surrounding tissue. The apparatus comprises: a pair of opposing electrically conductive cutting blades pivotally connected to allow for shearing action of any tissue confined between opposed cutting edges of the cutting blades wherein the is entirely covered with an electrically and thermally insulative material including its blunted tip and the other one of the pair of opposing cutting blades is entirely covered with an electrically and thermally insulative material except at its corresponding blunted tip; and a power source coupled to at least one of the pair of opposing cutting blades for electrically and thermally energizing at least one of the pair of blades.
An apparatus for cutting and cauterizing tissue during surgery while minimizing electrical and thermal contact of the apparatus with surrounding tissue. The apparatus comprises: a pair of opposing electrically conductive cutting blades pivotally connected to allow for shearing action of any tissue confined between opposed cutting edges of the cutting blades wherein the blades have blunted tips and wherein the pair of opposing cutting blades is entirely covered with an electrically and thermally insulative material except on confronting surfaces at the blunted tips; a power source having a power side that is electrically coupled to one of the pair of opposing cutting blades and having a ground side that is electrically coupled to the other one of the pair of opposing cutting blades for generating a cauterization current that flows through tissue trapped between the confronting surfaces at the blunted tips.